Kids, take note. I'm gonna smack some middle-aged wisdom down on your heads. Are you ready? Too bad.
If you love someone, but they don't know you exist, a big, grand, public gesture declaring your love is about the worst thing you could possibly do. You may have been getting mixed messages about this. In some TV shows and movies, it works out really well, especially in those proposal videos you've seen on YouTube. In other shows and movies, it doesn't work out so well, and everyone is embarrassed. That's the realistic one. The proposal videos are a special case, because you'll note those people have been dating for long enough that it makes sense for them. If you're trying to get someone's attention out of nowhere, grand gestures are not the way.
The flip side of this is that it's all going to fade away anyhow. When you get embarrassed like that, rest assured it will pass. In a few years, as long as you don't let that embarrassment define you, you'll laugh about it with your university friends, your spouse, your kids. Your life is most definitely not over.
The take-home message is this: if you're thinking of making a grand public declaration of love to someone who doesn't know you exist, here's what to do: go home, lock yourself in your room, think about something else - anything else - and don't come out until you stop feeling that urge.
Mokalus of Borg
PS - This is not much use as advice to young me.
PPS - Young me barely had the courage to daydream about this, let alone attempt a grand gesture.